: The best way to fill gaps is with slivers of the same wood. Often
: what I will do is use shavings from the block plane and glue
: them into the crack. That way they wet out the same color and
: they also age the same color as the surrounding wood. I also use
: plane shavings to cover blemishes. I dig out a very small recess
: and fill it in with a thick shaving, then sand flush.

I've tried that using Titebond II which was not the thing to do as the glue showed up after sanding showing the edges of the glue line around the piece I glued on.
What did work was using epoxy glue - that did not show the glue outline after sanding. I did such a poor job of b&c the strips (not-centered) that I was trying to find
an (easy-out) to fill or cover the gaps.
I am at the present time practicing the "angle transfer" that ET posted. That is a real helpful technique, it also helped me visualize the required angle that needs to be
hand planed. When I hand planed before, I had no idea what I was doing.
Thanks